Method of mixing and compounding rubber.



G. W. BULLEY.

METHOD OF MIXING AND COMPOUNDING-RUBBER.

APPLICATION FILED MAR. I5. 1917.

1 ,260'321. I latented Mar. 26,1918.

" and resident'of nois,

Compounding Rubber,

"'to, provide an improved method by which to intimately mixed anduniformly milling: ents suc means. of spaced rotating rolls betweenandaround which the rubber .is passed.-

enonen w. BUL EY, or cn'r'caed, rumors. Y

METHOD OI MIXING To all whom it may concern:

Be it known .that I, acitizen of the United'States of America,

Chicago, Cook county, Illihave inventeda certain new and usefulImprovement in Methods of ixing' and i of which the follow,- ing is aspecification.

My invention relates to the art of mixing and compounding rubber, and myobject is obtain a homogeneous mixture in which the compounding.-materials or ingredients are nated throughout the mass.

.It is the universal practice in mixing or rubber and compoundingingredias sulfur to manipulate the rubber of this manipulation theDuring the course sprinkles the compounds operator manually oringredients over themass ofrubber in-therolls as well as he'can.

of the ingredients 1s more or less indiscriminat and indefinite and nospecial attempt at uniformity is made. It has, however, been found to bethe only practical method introducing the com- This initial associationof the rubber ngenerally numerous. areas and localities in the'masswhich consist entirely or-almost entirely of the compounding materialsinan unm xed state. On account of i the peculiar nature of rubber thecompoundthe pockets ing materials must be literally squeezed orpressedinto'mixture or intimate association with the rubber. The operation of"the "mill or rolls above mentioned is 'suchthat;

or areas of compounding ingredients are of rubber and even spread tosome extent therein but these rolls do not bring portionsof the massinto relation with remote portions; hence the manipulation-is noteffective point of distribution and dissemination of the ingredients,and the non-uniformity 0;? distribution still exists. Now inan attemptto overcome this difficulty, the operator, in the exercise of his skill,will occasionally cut away a port on of the mass and place the severedportion in another relat ve position in'the mass, but these severedportions are Specification of Letters Patent.

, large and Gnonen BULLEY,

' dissemior extent This distribution ,stantly progressing in to acertain extent, manipulat-.

' localities where from the stand Ann comrounnrne nunnnn f Patentedital-.26, rare.

Application filed. March 15, 1917. Serial No.154,968.

contain in themselves the pockets or areas of unmixed compoundinginhence the bodily shiftingior transgredients,

"ference of these large portions to another locality in the mass doesnot eflect an inifinite 'distribution, so to speak, of the in gredients,but on the contrary merely changestheirrelative location in the mass.

.Eve'n repeated operations of this character does. not uniformlydistribute the ingrediants and hence localities in the mass will befound to be richer in compounding ingredients than other localities. Theeventual product or article is necessarily aiiected and Furthermore inthis method unsatisfactory. there is constantly the danger of over milling the rubber-that is to say the amount of manipulation 'taina passablemixture is likely to properties of the rubber to such an extentas tovary the length of time and treatment in the vulcanizing or curingprocess which 'the particular batch is intended to require, and as a,result the final according to standard.

My improved method I eliminates these various objections and produces athoroughly homogeneous mass in which-the distribution'of. the compoundsis infinite and uniform throughout thevmass. plish these results by moreeflfectively di- -recti-ng and bringing about the distribution of theingredients, and 'in carryin out my method I, mai tain a mass of ru betcona general direction at the same time'adding rubber and compoundingingredients to the mass, incrementby increment, either periodically orconstantly, and all the while manipulating and't r'iturating-the massduringits ress. about "a eomplete interchange and intermixture ofadjacent and remote portions of the progressing mass by shiftingcomparatively. small portions to new and; remote the' manipulation mixesthem with each other and-With the progressing mass and the incrementsadded to the mass, these relatively shifting and changing portions beingagain and again sub-dividedand the subdivision again distributed in themass whereby the compound ing ingredients are widel' and uniformlydisseminated throughout t e 'In the accompanying drawings I show amixing mill designed to carry out myim product will notbe I accomrog-'In addition'to this action I ring- Fig. 1 with the proved method, theapparatus, as a. mechanism, constituting the subject co-pendingapplication Serial filed March 10, 1917.

Referring to the drawings: Figure 1 is a view in side elevation of amixing machine for practising my method. Fig. 2 is a plan view on theline 22 of upper half of the casing removed.

Fig. 3 is a view of the feed end of the structure.

Fig. 1 is a view of the discharge end. Fig. 5 is a transverse section onthe line 55 of Fig. 1.

In the structure shown I provide two mixing and distributing members Gand D in the form of spiral screws which I confine Within tubularchambers or passages A and B formed in a suitable casing or housing E.These membersand their chambers are preferably, disposed longitudinallyand in parallel relation, and the members are journaled in suitablebearings at the ends of the casing so that they are: rotatable. Thechambers are arranged to intersect along their sides to provide acontinuous passage or line of communication therebetween and throughwhich the material is passed from one screw to the other. The rubber isfed into the hopper H at one end of the casing, increment by increment,and is taken up by the mixing member C and progressed along the chamber,the action of the screw being to triturate and manipulate the mass as itprogresses. The compounding materials are likewise fed into the hopperalong with the rubber and are of course worked into intimate mixturewith. the rubber by the action of the screw.

the other screw D which likewise manipulates the material and alsorc-transfers and shifts portionsto the screw G, this opera Lion takingplace as the mass progresses toward the other end of the mixing chambersand consequently intermixing the portions. I bring about thedistribution and redistribution of the portions of the mass by advancingor retarding portions o't'the progressing mass relatively to other porjtions, and in the structure shown this is acwith the sub-divisions ofother portions and again distributed. The mass, as a whole,

matter of a.

The screw, howeer, transfers or'shit'ts portions of the mass to isprogressing toward thedischarge end of the chambers, where the screwsforce the material through a die J which consists of a plate coveringthe ends of the chambers and provided with a plurality of small holes.These die openings or holes comminute the material and even assist to anextent in the mixing of the material. The

mixing members are driven at any suitable source through the medium ofgears L at one end of the casing. The mixing memin the same generaldirection, individually manipulating the portions of saidmass,relatively intermixing said portionsby transferring material fromeach portion'to the other. I

2. In the art of mixing and compounding rubber, the method of producinga thoroughly homogeneous mixture which consists in dividing the mass ofrubber and compounds into a plurality of streams, progressing saidstreams differentially in a general direction, and manipulating saidstreams individually relatively intermixing said streams byinterchanging the material there of and adding increments of rubber andcompounding ingredients to the mass. I

3. In the art of mixing rubber and compounds, the niethod'of producing athoroughly homogeneous mixture which consists di tlerentially in movinga plurality of masses of the material, individually manipulating themasses as they are moving, and intermixing and manipulating thematerials of the masses.

4. In the art of mixing rubber and compounds, the method of producing ahomogencous mixture which consists in individnail; manipulating aplurality of masses of 1 each mass to shift relatively and intermix wlthportlons of each other mass.

6. The method of mixing rubber and compounds which consists inindividually manipulating a plurality of masses of the 11121- terlal msuch close proxlmlty that the -1nanipulation thereof forces portions ofone pounds which consists in individually manipulating a plurality ofmasses of the mateyial in such close proximity that the llltlllplllniljll thereof forces portions of one mass into the other mass, andsimultaneously progressing the masses in the same general direction butat different speeds.

Signed. by me Chicago,jlllinois, this 5th day of March, 1917.

W. BULLEY.

